Hydraulic brake



Patented Nov. 22.0,y 1945 UNITED STATES PATENT )l-I.--`:lli'-.`

HYDRAULIC nannav Roy R..Bir.cheld, Shreveport, La. Application JanuaryL2, 194i, sentii-N0. szisioois. a claims. (el. 12s- 152) slide` whichaids inguidingr the piston rod for straight line sliding movement;

It is within the province ofthe disclosure to improve generally and tenhance the utility of devices of that type to which* the presentinvention appertains.

With the aboveandfotherobjectsinview, which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and inthe details of construction hereinafterdescribed and' claimed, it being understood' thatl changes inthe preciseembodiment of the invention herein disclosed, may be? madewithin thescopeof what is claimed, without departing from the spirit oftheinvention` In the accompanying'd-rawings:

Fig. 1 shows in section', a device constructed` inaccordance with theinvention, many parts remaining'in elevation;

Fig. 2` is a section taken through theactua-ting and guiding means,parts being left in elevation.

Fig. 3 is a cross section on1 the line 3'-3- oiA Fig. 1;

The letter ly designates a xed drum. The xed drum F includes aback plateI. 'I-het back plate Il is secured xedly, as indicated at 2; to anyaccessible` part of a vehicle. The back plate 2 is provided at itsperipheryr with aA laterally projecting' annular ila-nge 3. The backplate I1 has a central openingr 5f, for the reception of an axle (notshown). Approximately semi-circular linings 4= arev secured to the innersurface off' the flange 3. The numeral 6 designates approximate lysemi-circular shoes, the ends of one shoebeing spaced from the ends ofAthe other shoe, asFig. 1: shows. Each shoe Iiy comprises oppositelydis--posed= anglemembers BI, including' transverse anges 60 and inwardlylprojectingI flanges 62; On the'outerL surfaces off the flanges lill aredisposed'approxi-matel'yl semi-circular linings 'I-, having inwardly'extended tongues 63; disposed between thev ilanges 62- of theI shoes 6.Securing elements 64, suc-hy as rivets; connect theanges 62 and bind thetongues 63L between them: The

liningsl 'F and their; tongues 63 maybe formed by i folding apiece ofmaterial as shown in Fig. 3.v A drumis secured to th'e wheel of avehicle (not shown). The last-specified'`r drum includes' a lateral angeI8, received between the linings I and 4,

Intermediate their ends; thefshoes 6: have in.- WardlyA projecting ngers8'. The ngersf are sli'dably received'in keepers 9-secured tothe backplate I of the xed drum Guides IU- are secured to thel backl plate I.Spindle slidesl Il! ex.

tending from the ends oiffthel shoes 6, are mounted` for reciprocationin the guides I0; The spindles.

II are provided'with abutment pins I2". Cornpression springs` |24are-disposed aboutthe spindles II. The springs M" abut againstthevguides- I and against the pinsA Il2. springsy I6- is to4 keep theladjacent ends of the spindles II received' in outwardly converginggrooves Il51, formed in wedge-shaped spreaders lr6. The spreaders I6lare secured to the ends of: oppositely disposed piston rodslll". Sincethev inner ends of the-spindles Ifl'f are received inthe grooves I5 ofthe spreaders I6;` the piston rodsJ ITWill notl rotate in the structurewhich-carriesth'em, andvtov be described hereinafter:

The description of thepiston-rods I-I and asso ci-atedl parts will besuspended at this point inthe specification.

Spaced'` guides lgrareshown. The guides lill-aref cylindrical, andaresecured at ZIJ tothe back plate I of the fixed drum F. At their outerends, the guides I9-have integrali` heads 2?'I. The heads 2'I- carryglands 22. The piston rods I'I a-re mounted; for reciprocation in theglands 22.

Foot plates 24 are threaded at 25 upon thev adjacent ends of the guidesI9.

' The feet 214' ofth'e guides' I'llare supplied with projectingnecks26'; Packed' caps-21am threaded on the necks 26. ThecapsZT'areassembled* with the bran-ches 28fof a supply/conduit 29:Thesupply' conduit 29 furnishes liquid" under pressure.

A cylinder 3-0 is located within each guide I9f and' is formedintegrally with the corresponding necks 2li.V At itsI end' remote fromthe corresponding branch 28'; each cylinder t!!v is equipped with agland 3 I. The pistonrods I-'1 are mounted for reciprocation intheglands 3|. Pistons 3-2 are carried by the rods Il. The pistons 32reciprocate in the cylinders 30, responsive to the fluidV pressure inthe branches 218 of the supply conduit- 29: Packings 3-3 are secured at34 to the pistons32.

A cylindrical slide 35Y is, mountedv for reciprocation in the guide i9.The slide 35-`hasan integral head 36. The head 36 of the slide 35is'threaded at 31 on the piston rod Il, and therefore is connected toAth'e piston rod for reciprocation therewith. A compression spring 38 isdisposed about the 'piston rod VI, and is interposed between the head'2I of the guidev vI!! andthe head 36 of the slide 35. The functionr ofthe spring 38v is to carryv the piston rod I'I4- andthe piston 32Ainwardly, as th'e liquidI in the cylinder 3D recedes. the slide 35-participating in that movement.

s A footplate 39 is threaded'i'ntothe slide 35, or ssecured theretootherwise; A sleeve lilll is con- One function of the nected integrallyintermediate its ends, to the foot plate 39. The sleeve 40 is mountedfor reciprocation on the outside of. the cylinder 40. One end portion ofthe sleeve 40 is mounted to reciprocate in a circular guideway 4 I,formed in the neck 26 on th'e foot plate 24 of the guide I 9.

A guide bracket 42 appears in the drawings. The guide bracket 42includes a disk or body 43, which is threaded on the cylinder 33. Anannular rib 44 projects from the disk 43 of the bracket 42. Headedsecuring elements 45 are mounted in the rib 44. n

An annular washer plate 4'!4 is held in place by the securing elements45 and the sleeve 40 can reciprocate in the washer plate. A resilientcushion 48 is mounted jon Vthe washer plate 41 and is of annularform.The cushion 48 has an annular rib 49, abutting against the rib 44 on thedisk-like body 43 of the guide bracket 42. An inner ring 59 is threadedon the sleeve 4U to a xed position thereon, .an outer ring 5I beingsimilarly mounted within the cylindrical slide 35. The rings 5U and 5|are Vmounted for reciprocation on the rib 44 of the fixed guide bracket42. When the slide 35 and the sleeve 49 move down- Wardly, carrying withthem, respectively, the rings 5I and 50, the rings come into contactwith the cushion 48, and the downward movement of the slide 35 isterminated resiliently and without jar or shock.

As to the operation of the device, broadly considered, liquid underpressuregmoving through the conduit 29, traverses the branches 28, andthe piston 32, the rods I1 and the spreaders or actuators I 6 are moved,the spindles II, moving outwardly, and the springs I4 exerting pressureon the shoes 6, pressure being put on the annular flange I8 of the drumon the vehicle wheel (not shown), and a braking operation obviouslyresults. I'he flange 3..and the lining 4 form a dust guard.

In devices heretofore constructed; and embodying, broadly, some` of thestructure disclosed in this application, much diiculty has beenencountered in producing and sustaining a straight line movement in sucha partas the piston rod I'I, the travel of the piston 32 in the cylinder39 being irregular, wear and leakage resulting, and an unsatisfactorymovement `of such parts as the spreaders I 5 being produced. It will benoted that the guide-I9, which is fixed to the support I, isof'considerable diameter, relatively to the diameter of the cylinder 30,and the slide 35 is a large-diametered part also. Moreover, through theinstrumentalityv of the sleeve 49, which reciprocates on the iixedcylinder 30, the straight line movement of the piston rod I1 isadditionally promoted. The downward movement of the slide 35 iscushioned, because the rings 5I and 50 come into contact with the part48, which occupies a fixed position on the cylinder 39, since thecushion 48 is carried by the bracket 42 which, in turn, has a fixedmounting on the cylinder 3i).

What is claimed is:

1. In a-vehi'cle brake, a support and means for mounting it fixedly on avehicle, a wheel-carried drum, oppositely-disposed shoes `movablymounted on the support and engageable with the drum, oppositely-disposedguides of approximately cylindrical form` xedly mounted on'the supportand having inner and outer end wal-ls, cylinders carried by the innerend walls, means for supplying 'duid pressure tothe inner ends-of thecylinders,V approximately cylindrical slides mounted ier reciprocationin the guides and having llllll.'

and outer end walls, sleeves carried by the inner end Walls of theslides and mounted to reciprocate on the cylinders, guide rings secured,respectively, to the outer surfaces of the sleeves and to the innersurfaces of the slides, guide brackets secured to the cylinders andhaving annular ribs slidably received between the' corresponding rings,piston rods secured to the outer end Walls of the slides and receivedslidably in the outer end walls of the guides, pistons on the rods andslidalole in the cylinders, compression springs interposed between thelouter end Walls of the guides and of the slides, cushions secured to theribs and engageable with the rings, under the impulse 0f the springs,and coacting means on the rods and on the shoes for pressing the slicesagainst the drums when the pistons move outwardly.

2. In a vehicle brake, a support and means for mounting it iixedly on avehicle, a wheel-carried i drum, oppositely-disposed shoes movablymounted on the support and engageable with the drum, oppositely-disposedguides oi approximately cylindrical form iixedly mounted on the supportand having inner and outer end walls, cylinders carried by the inner endWalls, means for supplying fluid pressure to the inner ends of thecylinders, approximately cylindrical slides mounted for reciprocation inthe guides and having inner and outer end walls, sleeves carried by theinner end walls of the slides and mounted to reciprocate on thecylinders, guide rings secured, respectively, to the outer surfaces ofthe sleeves and to the inner surfaces of the slides, guide lbracketssecured to the cylinders and having annular ribs slidably receivedbetween the corresponding rings, rods secured to the outer end walls ofthe slides and received slidably in the outer end walls of the guides,pistons on the rods and slidable in the cylinders, andv coacting meanson the rods and on the shoes for pressing the shoes against the drumswhen thepistons move outwardly 3. In a vehicle brake, a support andmeans for mounting it iixedly on a vehicle, a wheel-carried drum, aVshoe mechanism movably mounted on the support and engageable with thedrum, oppositely-disposed guides of approximately cylindrical formiixedly mounted on the support and having inner and'outer end walls,cylinders carried -by the inner end walls, means for supplying iiuidpressure to' the inner ends of the cylinders, approximately cylindricalslides mounted forreciprocation in the guides and having inner and outerend walls, sleeves carried by the inner end walls of the slides andmounted to reciprocate on the cylinders, slidably-interengaged partscarried by the cylinders on the one hand, and by the sleeves and theslides on `the other hand, and Working in conjunction with theguides toconstrain the slides to straight-line movement, the sleeves and theslides being spaced transversely for the reception of saidslidably-interengaged parts, rods secured to the outer end walls of theslides and received slidably in the outer `end Walls of the guides,pistons on the rods and slidable in the cylinders, resilient means forforcing the pistons inwardly, cushions incorporated in saidslidably-interengaged parts and yieldably limiting the movement of theslides responsive to the-resilient means, and coacting means on the rodsand on the shoe mechanism for expanding the shoe mechanism against thedrum when the pistons move outwardly.

ROY R. BIRCHFIELD.;

